560 Bulletin 47, United States National Museum. 



diameter of eye. Maxillary scarcely dilated behind. Origin of dorsal 

 midway between tip of snout and dorsal mirror; base of dorsal equal to 

 length of postorbital part of head, and about equal to longest dorsal ray; 

 ventral origin slightly in advance of dorsal origin ; pectoral reaches 

 slightly beyond origin of anal. Scales smooth, those of the lateral line 

 scarcely larger than others. Mediolateral photophores 2 ; posterolaterals 

 2, the latter one above the other, or nearly so. Precaudals 4, in nearly 

 horizontal, though curved row, the last far below the end of the lateral 

 line ; anterolaterals 3, in nearly continuous line with lowest prepectoral 

 and mediolaterals ; number of superanals Tor 8. The pearly mirror upon 

 the upper edge of the caudal peduncle as long as the eye, and much longer 

 than the one extending from the end of the anal to the root of the caudal ; 

 slender and narrow, f as long as the head. Gill rakers 6 above and 12 

 below angle of first arch, longest f as long as eye. One specimen from 39 

 40' N., 71 35' W., in 538 fathoms. (Goode & Bean.) (gemmifer, bear- 

 ing buds or gems.) 



Lampanyctus gemmifer, GOODE & BEAN, Oceanic Ichthyology, 81, fig. 88, 1895, Grand Banks. 

 (Type, No. 35604. Coll. Albatross.) 



839. LAMPANYCTUS LACERTA (Goode & Bean). 



Head3; depth 5 ; eye moderate 31- D. 13; A. 15; scales about 36. 

 Greatest depth of head of its length. Snout somewhat obtuse, rounded, 

 with strong keel ; its length about i diameter of eye. Cleft of mouth 

 somewhat oblique, maxillary reaching to angle of preoperculum and 

 somewhat dilated. Origin of dorsal much nearer tip of snout than 

 root of caudal ; pectoral slender, its middle rays elongate ; ventrals 

 inserted slightly behind the origin of dorsal, and reach to base of first 

 anal ray ; anal inserted behind end of dorsal base ; caudal large, forked. 

 Photophores arranged somewhat as in M . punctatum. 



Mediolaterals 3 ; posterolateral 1 ; the former in an obliquely vertical 

 row, as in M. punctatum, the latter under the soft dorsal. Precaudals in 

 low horizontal line. Number of superanals 7 -f- 5. Three large pits in 

 the mandibles also show luminous qualities. Color apparently light 

 brown, the scales opalescent. Gulf Stream, at moderate depths ; not rare. 

 (Goode & Bean.) (lacerta, lizard.) 



Myctophumlacerta, GOODE & BEAN, Oceanic Ichthyology, 74, fig. 83, 1895, Gulf Stream, Lat. 

 28 38' 30" N. Long. 85 52' 30" W. (Type, No. 43778. Coll. Albatross.) 



260. LAMPADENA, Goode & Bean. 



Lampadena, GOODE & BEAN, Oceanic Ichthyology t 85, 1895, (speculigera). 



This genus or subgenus is very close to Lampanyctus, differing from the 

 latter chiefly in the small pectoral. From Nannobrachium, which it 

 approaches in this respect, the fact that the scales of the lateral line are 

 not enlarged, perhaps sufficiently distinguishes it. The anal fin is rather 

 short, its first ray being not in advance of the last ray of dorsal. As in 

 Lampanyctus and NannobracJiium, the scales are readily deciduous, and it 

 is not always easy to find the character of those in the lateral line from 

 preserved specimens. Probably Lampadena and Nannobrachium should 

 be merged in Lampanyctus. (/Id^Tn?, light ; afyv, gland.) 



